In the context of setting experiment group splits with decimal precision, the system is designed to limit the total number of buckets to 10,000, which allows for one digit of decimal precision.
When dealing with multiple variations, such as 32 in an experiment, it is recommended to assign 3.1% for 31 variants and 3.9% for the control group. This approach is considered acceptable for the experiment, and the slight difference in precision (e.g., 3.1% vs. 3.125%) is deemed negligible, especially in larger sample sizes where the difference might equate to a small number of users.
For experiments requiring more precise splits, alternating between 3.1% and 3.2% for every eighth variant is a suggested strategy. This allocation method is also applicable to more complex experimental designs, such as a 2-level fractional factorial experiment.
The key consideration is the statistical precision, which may be more critical depending on the user base size. It is important to note that the fixed number of buckets behind the scenes necessitates these allocation strategies.